<strong>1.25GHz at 1.8v = 900MHz at 1.3v. So that's the top speed of the TiBook that Apple could manage with the current chip, assuming they use the same low-voltage 7455.</strong><hr></blockquote>Could you explain this. I've been staring at it for 5 minutes trying to figure out what you mean and how you arrived at these numbers. Maybe it's the LSD.
<strong>Could you explain this. I've been staring at it for 5 minutes trying to figure out what you mean and how you arrived at these numbers. Maybe it's the LSD.</strong><hr></blockquote>
It's pretty simple: Within the limits of the processor spec, more electricity = higher clockrate. This is why Pentium IV PCs dim the lights in three counties when you switch them on. The relationship is not neatly linear, but in the range Mot is using it's close enough.
Supplied with 1.8 volts of electricity, a G4 can manage 1.25GHz. The same chip, fed 1.3 volts, tops out at about 1250 * 1.3/1.8 = 900 MHz, give or take.
PowerMac G4s get 1.8 volts of power. PowerBook G4s get 1.3.
Example: Going back to late spring, Mot had the G4 up to 1.1GHz. 1100 * 1.3/1.8 = 800MHz (again, give or take), which just happens to be the top speed of the PowerBook G4.
Some of the responses are taking my point too technically. Whether it's a 200mhz bump or 25% increase, that's not the main issue.
The issue is that from a marketing and financial standpoint, Apple isn't going to give us that monumental speed bump even if it had it available (unless they create a completely new SuperPro line).
They seem to be confident that they're currently competitive enough to stay the course with minor incremental speed bumps.
Thanks to going all dual and good marketing they might pull it off too. And this certainly helps their bottom line all along the way.
<strong>Some of the responses are taking my point too technically. Whether it's a 200mhz bump or 25% increase, that's not the main issue.
The issue is that from a marketing and financial standpoint, Apple isn't going to give us that monumental speed bump even if it had it available (unless they create a completely new SuperPro line).
They seem to be confident that they're currently competitive enough to stay the course with minor incremental speed bumps.
Thanks to going all dual and good marketing they might pull it off too. And this certainly helps their bottom line all along the way.</strong><hr></blockquote>
I don't think Apple's plan is to keep milking customers by gradually increasing the CPU speeds. Apple has been hurt once too often by jumping the gun on CPU offerings only to see Motorola drop the ball or the initial hype fizzle out by the time the units actually started shipping. So by offering only what they know for a fact that they can deliver in large quantities, they avoid those stock eroding blunders of the past (such as bumping the CPU speeds down by 50MHz on the original G4s). Remember, when Apple first rolled out the G4s, they topped out at 500MHz (which was dropped to 450MHz). The next model featured a dual 500MHz CPU, which shows Apple's willingness to offer a huge upgrade if they feel the need. It's possible they could have rolled out G5's, but I think Apple is a little hesitant to commit to the G5 after the debacle Motorola put them through with the G4. They'll wait until Moto has their act together with the G5, or they'll jump on IBM's Power4 (my personal preference).
Speed bumps are pointless when it comes to the major performance tests: animation, 2d/3d rendering, DVD rendering, etc. Going from 1.0 GHz to 1.25 GHz with all else (main memory speed; main memory to CPU throughput; etc.) being equal gains very little. You just get a snappier system for processing smaller sized data operations.
As for big jobs such as rendering and all, your overall system performance is ultimately measured by the overall data throughput, which is limited to the weakest link along the data processing chain. In this case, its the FSB interface on the PPC 7455.
Okay, so we've hashed this out in other threads. So, why bring it up here? Because CPU speed bumps alone make little difference!!! Hell, adding a second CPU makes little difference, other than the fact that the 2nd CPU can store some instructions and data in its cache to speed up small jobs. The big jobs are still chocked at the bottleneck.
So, what does Apple gain by adding a second processor to each PowerMac? A single 1.0 GHz PPC 7455 can attain a maximum THEORETICAL
So, what does Apple gain by adding a second processor to each PowerMac? A single 1.0 GHz PPC 7455 can attain a maximum THEORETICAL</strong><hr></blockquote>
The biggest thing that Apple gains with a second processor is marketing ammunition to say that they're just as fast or faster than the 2Ghz Pentium 4's.
Whether it's true or not is another issue.
And to another reply, I'm not suggesting Apple come out with anything before it's time. I'm merely speculating (as we all do) that it doesn't hurt Apple's bottom line by having gradual speed bumps as opposed to one gigantic one.
I'm thinking that Apple will bump it's lines only 3 times a year max. If you update too often there's always something to wait for.. but then I guess there always is.
On the topic of the scaling of the G4, I think (lately) it's been going really well. It's on track but it all depends on moto. I'm buying a dual 867 now. I dont care what's comming.
Never the less, moto doesn't just get off track, they go over the cliff. So I'm hoping to see (Seybold 2003 maybe?) a PPC made by IBM, power4 perhaps? IBM will be a lot more promising and consistant than moto. I think Moto's going down the tubes pretty soon too, so Apple better get out soon.
But like eirik pointed out. Speed bumps alone do nothing. Apple needs to be more aggresive in other areas, like this new thing called the FSB
Oh well. DDR and 167Mhz bus is something to be thankful though, I guess. Hopefully FW2 (gigawire?) and USB will make their debutes soon.
-ARW
"When we cut down all the trees and dry up all the streams, we will come to the realization that we cannot eat money."
Comments
<strong>1.25GHz at 1.8v = 900MHz at 1.3v. So that's the top speed of the TiBook that Apple could manage with the current chip, assuming they use the same low-voltage 7455.</strong><hr></blockquote>Could you explain this. I've been staring at it for 5 minutes trying to figure out what you mean and how you arrived at these numbers. Maybe it's the LSD.
<strong>Could you explain this. I've been staring at it for 5 minutes trying to figure out what you mean and how you arrived at these numbers. Maybe it's the LSD.</strong><hr></blockquote>
It's pretty simple: Within the limits of the processor spec, more electricity = higher clockrate. This is why Pentium IV PCs dim the lights in three counties when you switch them on.
Supplied with 1.8 volts of electricity, a G4 can manage 1.25GHz. The same chip, fed 1.3 volts, tops out at about 1250 * 1.3/1.8 = 900 MHz, give or take.
PowerMac G4s get 1.8 volts of power. PowerBook G4s get 1.3.
Example: Going back to late spring, Mot had the G4 up to 1.1GHz. 1100 * 1.3/1.8 = 800MHz (again, give or take), which just happens to be the top speed of the PowerBook G4.
Does that make sense?
The issue is that from a marketing and financial standpoint, Apple isn't going to give us that monumental speed bump even if it had it available (unless they create a completely new SuperPro line).
They seem to be confident that they're currently competitive enough to stay the course with minor incremental speed bumps.
Thanks to going all dual and good marketing they might pull it off too. And this certainly helps their bottom line all along the way.
<strong>Some of the responses are taking my point too technically. Whether it's a 200mhz bump or 25% increase, that's not the main issue.
The issue is that from a marketing and financial standpoint, Apple isn't going to give us that monumental speed bump even if it had it available (unless they create a completely new SuperPro line).
They seem to be confident that they're currently competitive enough to stay the course with minor incremental speed bumps.
Thanks to going all dual and good marketing they might pull it off too. And this certainly helps their bottom line all along the way.</strong><hr></blockquote>
I don't think Apple's plan is to keep milking customers by gradually increasing the CPU speeds. Apple has been hurt once too often by jumping the gun on CPU offerings only to see Motorola drop the ball or the initial hype fizzle out by the time the units actually started shipping. So by offering only what they know for a fact that they can deliver in large quantities, they avoid those stock eroding blunders of the past (such as bumping the CPU speeds down by 50MHz on the original G4s). Remember, when Apple first rolled out the G4s, they topped out at 500MHz (which was dropped to 450MHz). The next model featured a dual 500MHz CPU, which shows Apple's willingness to offer a huge upgrade if they feel the need. It's possible they could have rolled out G5's, but I think Apple is a little hesitant to commit to the G5 after the debacle Motorola put them through with the G4. They'll wait until Moto has their act together with the G5, or they'll jump on IBM's Power4 (my personal preference).
EVERY chip only increases by 200MHz or so each update. Radical speed bumps require brand new CPUs.
Sometime in 2003 (IMHO), a brand new CPU will appear. And it will see the return of smoked bunnies to resturant menus.
Barto
As for big jobs such as rendering and all, your overall system performance is ultimately measured by the overall data throughput, which is limited to the weakest link along the data processing chain. In this case, its the FSB interface on the PPC 7455.
Okay, so we've hashed this out in other threads. So, why bring it up here? Because CPU speed bumps alone make little difference!!! Hell, adding a second CPU makes little difference, other than the fact that the 2nd CPU can store some instructions and data in its cache to speed up small jobs. The big jobs are still chocked at the bottleneck.
So, what does Apple gain by adding a second processor to each PowerMac? A single 1.0 GHz PPC 7455 can attain a maximum THEORETICAL
<strong>
So, what does Apple gain by adding a second processor to each PowerMac? A single 1.0 GHz PPC 7455 can attain a maximum THEORETICAL</strong><hr></blockquote>
The biggest thing that Apple gains with a second processor is marketing ammunition to say that they're just as fast or faster than the 2Ghz Pentium 4's.
Whether it's true or not is another issue.
And to another reply, I'm not suggesting Apple come out with anything before it's time. I'm merely speculating (as we all do) that it doesn't hurt Apple's bottom line by having gradual speed bumps as opposed to one gigantic one.
On the topic of the scaling of the G4, I think (lately) it's been going really well. It's on track but it all depends on moto. I'm buying a dual 867 now. I dont care what's comming.
Never the less, moto doesn't just get off track, they go over the cliff. So I'm hoping to see (Seybold 2003 maybe?) a PPC made by IBM, power4 perhaps? IBM will be a lot more promising and consistant than moto. I think Moto's going down the tubes pretty soon too, so Apple better get out soon.
But like eirik pointed out. Speed bumps alone do nothing. Apple needs to be more aggresive in other areas, like this new thing called the FSB
Oh well. DDR and 167Mhz bus is something to be thankful though, I guess. Hopefully FW2 (gigawire?) and USB will make their debutes soon.
-ARW
"When we cut down all the trees and dry up all the streams, we will come to the realization that we cannot eat money."